Vasectomy is a surgical procedure that interrupts the continuity of the vas deferens (vas) in order to prevent sperm from passing from the testis into the ejaculate, thus preventing sperm from uniting with the ova. Vasectomy is the most effective contraceptive method available to men. While vasectomy is considered to be a permanent procedure, it can be reversed with varying degrees of success.
There are many surgical techniques that have been devised for vasectomies, with varying degrees of effectiveness. Recent research has confirmed that fascial interposition increases the effectiveness of ligation and excision, and the lowest failure rates for vasectomy have been reported by physicians using a combination of cautery and fascial interposition. As used herein, “fascial interposition” refers to the surgical technique of interposing a layer of fascial membrane, from the fascial sheath which surrounds the vas, between the two cut ends of the vas.
The inventors have found that the most common cause of vasectomy failure is early recanalization. As used herein, “recanalization” refers to the spontaneous regrowth of one or more tubules between the cut ends of the vas deferens. It occurs most commonly within three weeks to two months after vasectomy and is diagnosed by the successful passage of sperm from the testes into the semen.
When properly done, fascial interposition prevents recanalization by interposing a tissue barrier between the cut ends of the vas. However, the surgical technique of fascial interposition is time-consuming and requires considerable surgical skill. Many surgeons consider fascial interposition to be too difficult. In addition, fascial interposition may be difficult to implement in men who have a history of bacterial infections such as sexually transmitted infections, or parasitic infections, such as filariasis, which may cause fibrotic changes in scrotal tissues.